Shouldn't his helmet have protected him, as in slvoid's case? Might it have been a defective or broken helmet? Could he have been wearing it improperly? Or was this just one of those extenuating cases that helmets won't cover, without spending inordinately more money in their design and manufacture? (Probably it could have been any of these, but we'll never know.)

Not trying to open the wear-or-not-wear one debate, I'm just trying to figure out why my expectation of its protective ability was seemingly not met here.